Yeah it just means (G)reat (Br)itain. You have to use 3 letters as the acronyms in the Olympic games, that is why it isn't the UK (which means northern ireland, wales, england and scotland) even though N. Ireland can participate in the GB team (great britain actually excludes N. Ireland).
It's short term like Great Britain G for Great and then BR the 1st 2 letters in Britain .
(the capitals are the initials GBR) Great BRitain
great brittain. you formally use 3 letters when representing a country and city although some (cities) informally use 2 letters
I know the GB in GBR is Great Britain but what does the R stand for?